Instrument-core of rhombic or lens-shaped section.



100. 728,500. l -V `PATENTED MAY 19.1903.

. `W. SABBL.

INSTRUMENMORB 0F RHOMBIG 0R LENS SHMEJQ,y sBOTION.

. APPLICATION FILED SEPT. 22, 1902.

N0 MBEL.

f f 5 q t 5 *a #60065566 Y, K JNWZY UNITED STATES VWILHELM SABEL, OF

' Patentedivray 19, 1903.

BERLIN, GERMANY.

INSTRUMENT-CORE OF RHOMBIC OR LENS-SHAPED SECTION.

SPECIFICATION forming` part of Letters Patent N o. 728,500, dated May 19, 1903.

Application filed September 22, 1902. Serial No. 124,436. (No model.)

To @Z5 whom t 11i/ty concern: s

Be it known that I, WILHELM SABEL, a citizen of the German Empire, residing at N o. lOl Kniggratzerstrasse, Berlin, Germany, have invented certain new and useful Improvements in Pencil or other vVVritingror Drawing Instrument Cores of Rhombic or Lens-Shaped Section, of which the following is a specification. t

This invention relates to improvements in pencil or like cores, and has for its object to increase the lasting properties of the points of such pencils or like instruments.

The especial features of the invention consist in the formation of the pencil writing or drawing instrument core by giving it a rhombic or lens-shaped section vwith two sharp longitudinal edges, by means of which two writing or drawing points may be formed havinga greater resistance with regard to breaking than the hitherto-employed round point. To this end anotch similar to the notches in asaw-blade is cut into the end of. the core, preferably by means of a three-cornered file.

In the accompanying drawings, Figure lis a perspective view of a pencil with the newy Figs. 2 and 3 show different sections of the core.

Referring to the drawings, the pencil-core a, of metal, graphite, chalk, or the like, is of arhombic, Fig. 2, or lens-shaped section,

Fig. 3, and consequently presents two sharp edges b and c. This pencil-core is, however, not sharpened to a round point,as customary heretofore, but receives a deep notch d, as shown in Fig. l, which is effected, for instance, by means of a three-cornered file in moving the same crosswise to aline drawn -at right angles from the sharp edge e to the edge f.'

It will be apparent that thereby two triangular vpoints e and fare produced, which are much stronger than the hitherto-used round points. ening of the pencil in the manner above described will not be necessary until both points have been worn down, from which it will be apparent that a pencil provided with the improved core can be used double the time with# out repointing than a round pencil or a fiat pencil with a round point.

WhatI claim, and desire to secure by Letters Patent of the United States, is-

An improved pencil or other Writing or drawing instrument core, having a attened shape, which presents two opposite bulged surfaces and two sharp longitudinal edges in which said lateral surfaces intersect under an acute angle, substantially as described and for the purpose set forth.

In testimony whereof I ax my signature.

WILHELM SABEL. In presence of WOLDEMAR HAUPT, OTTO BEER.

A further subsequent sharp` 

